tents CAN be great... as you can have a bit more control over your environment ie, airflow, smell, light-proofing... plus IMO they are an easy way to keep things contained to one specific area for the most part ....
some closets have no or little exhaust, basements are dank and can raise mold and mildew issues, rooms are great if you can keep all the heat and humidity down ...
all in all i just feel like a tent requires less labor (especially if you're not mechanically inclined like me) and are designed for growing making it a bit easier ...
here's the catch .....you SHOULD buy a good tent ... cheap ones off ebay work ...but look out for light leaks, tears, and overall poor quality.
just my few cents..