All perfect praise be to Allah
I will talk with Sunni point of view.
Alright, this topic is a huge and old topic and there are full books on this topic from the time it started it is one of the most often debated topics.
Now i think we should analyze the sum or the base of all this difference of opinion.
Now,
First come those who say it is good to do so, one group in them says it is not biddah and they say that it is like using computer(as said in an above answer). But they are basically wrong and are some how have low knowledge and understanding of islam. Because there is difference in Biddaat of world and biddat in deen(innovation in worldly things and innovation in deen)..
Biddat, which are so many times discussed and discouraged in ahadees are not innovation of world but are innovation of deen.
Lets ahve a look at some ahadees.
The Prophet (ﷺ) said, "I am your predecessor at the Lake-Fount(Houz al-kausar), and
some of you will be brought in front of me till I will see them and
then they will be taken away from me and I will say, 'O Lord, my
companions!' It will be said, 'You do not know what they did after you
had left.'
An-Numan bin Abi Aiyash, on hearing me, said. "Did you hear this
from Sahl?" I said, "Yes." He said, " I bear witness that I heard Abu
Sa`id Al-Khudri saying the same, adding that the Prophet (ﷺ) said: 'I
will say: They are of me (i.e. my followers). It will be said, 'You do
not know what they innovated (new things) in the religion after you
left'. I will say, 'Far removed, far removed (from mercy), those who
changed (in their religion) after me."
Sahih al-Bukhari 6576 and 6584 (their are multiple ahadees with more or less same meaning of this in this chapter of bukhari)
Allah's Messenger (ﷺ) said, "If somebody innovates something which is
not in our religion, that thing is
rejected."
Sahih al-Bukhari 2697
These and many more ahadees like these show that there is something called BIDDAH(innovation) which is very bad and a muslim must not do it. If we say something like it is like using computer, than do these ahadees restrain us from inventing or using anything? or any new thing? No, the reality is these ahadees are about the new inventions in deen. As there is a hdees in which Abdullah bin umer see some people counting tasbeehat on some e=stones etc in masjid al nabvi after death of prophet muhammad, and he got angry on them and said they were doing biddah.
Now, come those people who say, it is biddat hasna, they also have some evidences for this, main is the evidence that Umer R.A started the proper Traveeh prayer in masjid al-nabvi and in all islamic state, and that was new thing and there was nothing like this before.
But this also is not logical, because traveeh was prayed with jamaa'at by prophet muhammad 3 nights and he said after that, that this Allah so much liked this prayer, that i feared this traveeh slaat may get FARZ on you, so i didn't came to lead you in this prayer. So, Hazrat Umer R.A starting proper raveeh jamaat was not innovation or new thing, it was just revival of sunnah.
Now comes the people who say that this is biddah, and innovation in religion and must not be done. by above ahadees and many many other ahadees their point of view seems to be more strong(at least in my understanding).
PS: lets say for the skae of argument, if this IS biddah, than in the judgement day i will face all that humiliation on HOOZ Al-KAUSER. All also all other ahdees on biddat apply on me if i am doing it. Now, lets say if this was not that biddah and was actually BIDDAT HASNA, and i was not doing it. I have nothing more to loose, i didn't do it, also no sahaba or taabi or taba tabi did it either, so i am on a safe side and can still go to paradise. So, it makes sense to stay away from this to be on safe side. even if above ahadees on topic does not convince me.
This is a highly controvertial topic and we can't debate here on this. This is my opinion one can agree or dis-agree. But we just can't debate here.
Allah knows Best