I landed here after encountering the same issue and was shocked and dismayed to see DTS saying “does it really matter?” Flippant remark, full stop.
But it’s easy to see how it matters. If you’re measuring performance, good luck since now you have pollution from a second instance of yourself! If you’re debugging something, you have to wonder which of the two instances to kill and which the debugger will actually debug. And, imagine an app that writes to a file at startup (very common, preference files or logs or the list goes on) now suddenly battling another copy of itself. These things all hit me immediately with this.