Because it was cheap. I had all 3 of mine at the same time for a little bit.
My first one was a GS, and despite the horrible excuse for an automatic transmission I really enjoyed that car. I paid $1100 for it, w/ 150k miles. A few months after I bought it, the stock exhaust basically fell off so I got an Ebay exhaust. The hood latch decided to stop working so I took it out and put on some hood pins. I got a cold air intake. Found some 17" wheels with tires for $100. I ended up selling the wheels for $110 after using them for a while. Sold the car 2.5 years later for $1000 w/175k miles.
Second one was a beautiful LS I got for $3800 w/ 92k miles. Perfect paint, no rust, stock engine, no accidents, OEM optional lip and sides. It was one of the cleanest ones I've seen. 5 days later some old lady in the center (left turn) lane decided she needed to go to the bank and made a right turn (from the center lane) across 2 lanes without looking. I couldn't react in time to prevent a collision and T-boned her @ 40mph. After another $1000 in parts and months of trying to save it, I had to let it go, it had some pretty serious frame damage and was gonna be too much to fix.
Third one was a fairly clean GS-R shell I got for $1900 (I overpaid but it was the only option). The engine and transmission from the LS still worked fine, the interior was flawless, the Koni suspension was not bad, exhaust made a great sound etc. I took the LS and took everything out and put it in the GS-R, along with another $1000 in parts. I traded the LS shell for some parts for the GS-R and drove it for a while. I recently sold it for $2400.
I no longer have an Integra.