Is it bad? as in evil? probably not. but is it the best? is it what God instructs in scripture? a review of scripture in the book of Acts and in the epistles reveals that people were meeting in homes.
They may have met or first heard Paul and Barnabas or others in synagogues, but those that continued in the word ended up meeting in homes for the most part.
We do not see the apostle Paul or anyone else collecting money to build buildings.
Offerings were made to further the gospel, not to build things.
Homes made the most sense. In Philippi, for instance, Lydia believed, that was it for a time, of course, her household probably believed also, but why build something when homes were already there and ready to go?
The jailer believed, Paul and Silas spoke to all those in his house, who may have believed, but why build something for say a man and his family when they already have their home for a meeting place?
If a person does not want to be noticed or would rather be neglected, a mega church is a great place to go, but if a person wants to be a part of something and make a difference a home fellowship is the only way to go, except of course, for an occasional larger meeting.