The marginal costs of dedicated infrastructure teams is the legion of tickets that product teams want fixed first. The signup team hates that signups take seconds to process instead of milliseconds so there's desire to rebuild the batch job runner, the identity teams want you to make a richer capability-based authz system so that they can sell capabilities as a customer facing product, etc. These infra teams need to justify rebuilding infra like Docker against the marginal opportunities of creating new things for product teams.