There's plenty of incentives to run your own bitcoin node, the main one being privacy.
You don't need to run a monero node to be private (network-wise).
On that basis alone, there should be much more bitcoin nodes.
quotingSnapshot December 5
nevent1q…p4hq
#Monero Nodes: 22537
(Source: monero.fail)
#Bitcoin Nodes: 17001
(Source: bitnodes.io)