User blog comment:Bluegear93/Volus/@comment-1786741-20121009221651/@comment-4721065-20121010091955

Well, volus are the richest race and their territory has expanded ten times since they have joined the Council. This means that there probably were enough rich volus in the peacetime who experimented with biotics purely for shock/prestige value without intending to use them in combat or to protect themselves with barriers should they ever get ambushed without guards.

Also, while turians are supposed to provide most of their defence, I doubt that volus would be content with letting that opportunity go, especially if this was their only chance to actually do something in combat. To use a real-life example, civilians usually understand that they're nowhere near as good with firearms as trained police forces and that simply donating to police can be a better way to keep up law & order than to buy their own guns. Nevertheless, there plenty of gun owners in every country where the regulations are sufficienly lax.

Finally, it is stated that turians distrust biotics and that it doesn't form a large part of their military strategy. Volus might also have not have offered biotics to them because they thought turian military didn't need them or they would get too powerful with them and they wanted to keep a certain leverage.