There's a lot more to Transnistria. Russia wants it as a strategic point of access to Europe. There are roads purposely build for quick access with tanks (big, heavy, concrete roads, reinforced with rebar - your car usually makes a clunking sound as if you're on a train). So they support the region with preferential natural gas prices (sometimes the bill gets completely tagged to Republic of Moldova). At the time when URSS collapsed, and the split happened - most of the heavy industry was on the Transnistrean side (including weapons factories), so it was big loss for Republic of Moldova. The Army 14 of the URSS never left Transnistria, and Russia still refused to call them back. [ https://ro.wikipedia.org/wiki/Implicarea_Armatei_a_14-a_%C3%... ]
It's a semi-lawless land, used sometimes as a hiding spot for criminals, assassins, etc. Gun trafficking is at home there. When on bike, I managed once to pass the border without being checked (and I didn't notice I didn't have my papers with me, I almost got stuck in there) - you're basically at the whims of the border patrols.
There are a few villages that belong administratively to Republic of Moldova (I visited Coșnița [coshnitza] with a friend, that is one such village) - this state of affair came with great cost of lives, and people there still remember the price they paid. Tensions sometimes get high - in 2012 a drunk guy was shot and killed by the border patrol, as he was traversing the bridge - people were literally picking up forks and scythes to avenge him [ http://www.ziare.com/europa/moldova/moldovean-impuscat-de-ru...]
