The problem with the original sentence is that it's elliptical—but with an incorrect subject-verb agreement.
When we form an elliptical sentence, we assume that the first part is implied in subsequent parts.
There is interesting daily life in the streets and alleys, and also [there is] unique places such as old or coloured houses and attractions between streets.
Since the sentence starts with there is, leaving it out of the second part implies that it should be silently repeated (or assumed), in the second part—except that doing so would not be correct in this case.
In order to correct the problem, be explicit rather than using ellipsis:
There is interesting daily life in the streets and alleys, and there are also unique places such as old or coloured houses and attractions between streets.
That corrects the problem with the grammar. Whether or not the sentence should be rewritten in general or not is something else. It seems that your colleague didn't make the simple correction needed—but decided to make more significant changes. That's more a matter of opinion on their part.